Synthesis and radiofluorination of novel fluoren-9-one based derivatives for the imaging of α7 nicotinic acetylcholine receptor with PET

Bioorg Med Chem Lett. 2018 May 15;28(9):1471-1475. doi: 10.1016/j.bmcl.2018.03.081. Epub 2018 Mar 29.


By structure-activity relationship studies on the tilorone scaffold, the 'one armed' substituted dibenzothiophenes and the fluoren-9-ones were identified as the most potential α7 nAChR ligands. While the suitability of dibenzothiophene derivatives as PET tracers is recognized, the potential of fluoren-9-ones is insufficiently investigated. We herein report on a series of fluoren-9-one based derivatives targeting α7 nAChR with compounds 8a and 8c possessing the highest affinity and selectivity. Accordingly, with [18F]8a and [18F]8c we designed and initially evaluated the first fluoren-9-one derived α7 nAChR selective PET ligands. A future application of these radioligands is facilitated by the herein presented successful implementation of fully automated radiosynthesis.

Keywords: Dibenzothiophenes; Fluoren-9-one; PET; Radiofluorination; α7 nAChR.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Fluorenes / chemical synthesis
  • Fluorenes / chemistry*
  • Halogenation
  • Humans
  • Molecular Structure
  • Positron-Emission Tomography*
  • alpha7 Nicotinic Acetylcholine Receptor / analysis*
  • alpha7 Nicotinic Acetylcholine Receptor / chemistry
  • alpha7 Nicotinic Acetylcholine Receptor / metabolism


  • Fluorenes
  • alpha7 Nicotinic Acetylcholine Receptor
  • 9-fluorenone